People with sleep apnea may have a higher risk of developing pneumonia than those without, according to a recent study HealthDay reported.

Sleep apnea is characterized by disrupted sleep, caused when the upper airway becomes obstructed by soft tissue, cutting off oxygen. It has been linked to several types of heart disease and cognitive impairment. People with obstructive sleep apnea are at higher risk of aspiration while sleeping.

"This study showed that sleep apnea is an independent risk factor for incident pneumonia," wrote Dr. Vincent Yi-Fong Su and Dr. Kun-Ta Chou of the department of chest medicine at Taipei Veterans General Hospital in Taiwan. "Our results also demonstrated an exposure-response relation in that patients with more severe sleep apnea may have a higher risk of pneumonia than patients with sleep apnea of milder severity."

Taiwanese researchers followed 34,100 patients - 6,816 people who had sleep apnea and 27,284 who did not - for 11 years.

 They found that 9 percent of the sleep apnea group developed pneumonia, compare to less than 8 percent of those without the sleep disorder.

The people that developed pneumonia were older and had more comorbidities such as heart disease, diabetes, dementia and other diseases.

Researchers suggest that the higher incidence of pneumonia in people with sleep apnea could be because of increased risk of aspirating contents or liquid from the throat.